Ionic thermal dissipation device

ABSTRACT

An ionic thermal dissipation device includes an ionic wind generating system and a power system to drive the ionic wind generating system. The power system first converts external direct current power signals into alternating current (AC) power signals, and boosts the AC power signals. The power system doubles voltage of the boosted AC power signals, and rectifies the boosted AC power signals to generate high voltage direct current power signals to drive the ionic wind generating system. The power system also detects current signals generated by ion excitation of the ionic wind generating system, and regulates the high voltage direct current power signals according to the detected current signals.

BACKGROUND

1. Technical Field

The disclosure relates to thermal dissipation devices, and particularlyto an ionic thermal dissipation device.

2. Description of Related Art

Ionic thermal dissipation devices usually utilize voltage feedback.Thus, the ionic thermal dissipation devices regulate ionic excitationvoltage according to feedback voltage to control velocity of generatedionic wind. However, temperature may influence the ionic excitationvoltage, that is, the ionic thermal dissipation devices with same ionicexcitation voltage may have different velocities of ionic wind indifferent temperature environments. Thus, the voltage feedback cannoteffectively control the velocity of ionic wind of the ionic dissipationdevices. In addition, utilizing the voltage feedback, the ionicexcitation voltages of the ionic thermal dissipation devices are set atpredetermined values, such as, 5000˜6000V, according to neededvelocities of ionic wind, which results in arcing when the temperaturechanges.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of one embodiment of an ionic thermaldissipation device as disclosed.

FIG. 2 is a schematic diagram of another embodiment of an ionic thermaldissipation device as disclosed.

FIG. 3 is a circuit diagram of one embodiment of a current feedbackcircuit of an ionic thermal dissipation device.

DETAILED DESCRIPTION

FIG. 1 is a schematic diagram of one embodiment of an ionic thermaldissipation device 10 as disclosed. The ionic thermal dissipation device10 includes a power system 100 and an ionic wind generating system 200.The power system 100 converts external direct current (DC) power signalsVin into high voltage DC power signals Vout, where the high voltage DCpower signals Vout drive the ionic wind generating system 200 togenerate ionic wind to dissipate heat. In one embodiment, the powersystem 100 includes a power stage circuit 110, a pulse width modulation(PWM) controller 120, a transformer 130, a voltage double and rectifiercircuit 140, and a current feedback circuit 150. The ionic windgenerating system 200 includes an emitting pole 210 and a receiving pole220.

In one embodiment, the power stage circuit 110 includes DC toalternating current (AC) converter circuit to convert the external DCpower signals Vin into AC power signals. In alternative embodiments, thepower stage circuit 110 further includes a DC/DC converter circuit toregulate voltage level of the external DC power signals Vin. The PWMcontroller 120 controls the power stage circuit 110 to regulate voltageand frequency of the AC power signals output by the power stage circuit110. The transformer 130 may be a boost transformer to boost the ACpower signals. The voltage double and rectifier circuit 140 doublesvoltage of the boosted AC power signals and rectifies the boosted ACpower signals to generate the high voltage DC power signals Vout todrive the ionic wind generating system 200.

The emitting pole 210 of the ionic wind generating system 200 receivesthe high voltage DC power signals Vout, and excites air ionization togenerate positive ions or negative ions. The positive ions or thenegative ions move from the emitting pole 210 to the receiving pole 220,causing the air to generate the ionic wind. At the same time, themovement of the positive ions or the negative ions between the emittingpole 210 and the receiving pole 220 form minor currents, such as, 0.1 to0.5 mA, that is, current signals generated by ion excitation. If adistance between the emitting pole 210 and the receiving pole 220 isfixed, the current signals are proportionate to ion concentration of theionic wind generating system 200. That is, the current signals areproportionate to velocity of the ionic wind. For example, when thedistance between the emitting pole 210 and receiving pole 220 is 7 mm,if the current signal generated by the ion excitation is changed from0.1 mA to 0.5 mA, the velocity of the ionic wind needs to be changedfrom 1.4 m/s to 2.0 m/s. In addition, when the ionic thermal dissipationdevice 10 arcs, the current signal becomes apparently high due todischarge between the emitting pole 210 and the receiving pole 220.

The current feedback circuit 150 detects the current signals generatedby the ion excitation of the ionic wind generating system 10, andfeedbacks the detected current signals to the PWM controller 120. Thus,the PWM controller 120 regulates the voltage and the frequency of the ACpower signals output by the power stage circuit 110 to control thevoltage of the high voltage DC power signals Vout output by the powersystem 100. Because environmental temperatures have no influence on thecurrent signals generated by the ion excitation, thus, current feedbackcan effectively regulate velocity of the ionic wind of the ionic windgenerating system 200. In addition, when the current signals exceed apredetermined value, for example 1A, the PWM controller 120 determinesthe ionic thermal dissipation device 10 arcs, and turns off the powerstage circuit 110 to implement arcing protection.

As shown in FIG. 1, the current feedback circuit 150 is connected to alow voltage end of a secondary winding of the transformer 130 and thePWM controller 120. The current feedback circuit 150 detects the currentsignals from the low voltage end of the secondary winding of thetransformer 130, and feedbacks the detected current signals to the PWMcontroller 120. As shown in FIG. 3, the current feedback circuit 150includes a diode D1, a resistor R1, and a capacitor C1. The diode D1detects and rectifies the current signals, and has an anode connected tothe low voltage end of the secondary winding of the transformer 130 anda cathode connected to the PWM controller 120. The capacitor C1 isconnected between the cathode of the diode D1 and the ground, andsuppresses noises of the current signals. The resistor R1 is connectedbetween the cathode of the diode D1 and the ground, and forms voltagesignals according to the current signals to control the PWM controller120.

FIG. 2 is a schematic diagram of another embodiment of an ionic thermaldissipation device 10′ as disclosed. In this embodiment, the currentfeedback circuit 150 is connected to the receiving pole 220 of the ionicwind generating circuit 200 and the PWM controller 120, and otherstructures and connections of the ionic thermal dissipation device 10′are similar to those of the ionic thermal dissipation device 10 ofFIG. 1. Therefore, descriptions are omitted here. The current feedbackcircuit 150 detects the current signals from the receiving pole 220 ofthe ionic wind generating system 200, and feedbacks the detected currentsignals to the PWM controller 120. Accordingly, the anode of the diodeD1 of the current feedback circuit 150 is connected to the receivingpole 220 of the ionic wind generating system 200, and the cathode of thediode D1 is connected to the PWM controller 120.

The ionic thermal dissipation devices 10 and 10′ utilize currentfeedback, which avoids influence of environmental temperatures, andeffectively control velocity of the ionic wind of the ionic thermaldissipation devices 10 and 10′ and implement arcing protection.

The foregoing disclosure of various embodiments has been presented forpurposes of illustration and description. It is not intended to beexhaustive or to limit the invention to the precise forms disclosed.Many variations and modifications of the embodiments described hereinwill be apparent to one of ordinary skill in the art in light of theabove disclosure. The scope of the invention is to be defined only bythe claims appended hereto and their equivalents.

1. An ionic thermal dissipation device, comprising: an ionic windgenerating system; and a power system, the power system comprising: apower stage circuit, operable to converting external direct currentpower signals into alternating current (AC) power signals; atransformer, operable to boost the AC power signals; a voltage doubleand rectifier circuit, operable to double voltage of the boosted ACpower signals and rectify the boosted AC power signals to generate highvoltage direct current power signals suitable to drive the ionic windgenerating system; a current feedback circuit, operable to detectcurrent signals generated by ion excitation of the ionic wind generatingsystem; and a pulse width modulation (PWM) controller, operable tocontrol the power stage circuit to regulate the high voltage directcurrent power signals according to the detected current signals.
 2. Theionic thermal dissipation device of claim 1, wherein the currentfeedback circuit is connected to a low voltage end of a secondarywinding of the transformer and the PWM controller, and detects thecurrent signals from the low voltage end of the secondary winding of thetransformer and feedbacks the detected current signals to the PWMcontroller.
 3. The ionic thermal dissipation device of claim 2, whereinthe current feedback circuit comprises: a diode, comprising an anodeconnected to the low voltage end of the secondary winding of thetransformer and a cathode connected to the PWM controller; a resistor,connected between the cathode of the diode and the ground; and acapacitor, connected between the cathode of the diode and the ground. 4.The ionic thermal dissipation device of claim 1, wherein the ionic windgenerating system comprises: an emitting pole, operable to receive thehigh voltage direct current power signals to excite ions; and anreceiving pole, operable to receive the ions excited by the emittingpole.
 5. The ionic thermal dissipation device of claim 4, wherein thecurrent feedback circuit is connected to the receiving pole of the ionicwind generating system and the PWM controller, and detects the currentsignals from the receiving pole of ionic wind generating system andfeedbacks the detected current signals to the PWM controller.
 6. Theionic thermal dissipation device of claim 5, wherein the currentfeedback circuit comprises: a diode, comprising an anode connected tothe receiving pole of the ionic wind generating system and a cathodeconnected to the PWM controller; a resistor, connected between thecathode of the diode and the ground; and a capacitor, connected betweenthe cathode of the diode and the ground.